import java.util.Random;

public class test {

    public static void main(String[] args) {

        int j = 0;
        for (int k = 0; k < 10000; k++) {
            int i = new Random().nextInt(40);
            if(i>=20){
                j++;
            }
        }

        System.out.println("恭喜你：获奖的id："+j);

    }
}
